NIH/NIGMS K12 Postdoctoral Fellowship, Tufts University School of Medicine; Ph.D., University of Wisconsin-Madison; B.A., Cornell College
What I Love About Emmanuel:
I love the breadth and depth of learning that is ingrained within the liberal arts and sciences curriculum. I appreciate the personalized connection between faculty and students in the classroom and research laboratory. I relish our dynamic campus community that embraces its rich history and surrounding Boston resources.
International + National Conferences
PI External Funding
Student External Funding
PI Awards + Recognition
Gene regulation is integral to biological control, and transcription is one of the earliest and most powerful steps to modulate gene expression. During productive transcription of mRNA genes in eukaryotes, RNA Polymerase II (Pol II) initiates at a promoter and elongates RNA through the gene open reading frame (ORF). Pol II transcription termination is coupled with mRNA 3’-end processing and polyadenylation, which has been best studied in the model eukaryote yeast (Fig. 1A). Gene downregulation can occur via premature transcription termination of RNA polymerase (i.e. attenuation), which limits synthesis of full-length mRNA and thereby restricts protein production (Fig. 1B). As a testament to its biological utility, attenuation is one of the most ancient and widespread forms of gene regulation, spanning all three domains of life and viruses. Once thought to be rare, attenuation of Pol II transcription in eukaryotes appears even more prevalent than in bacteria, occurring at 10-15% of mRNA genes in yeast and higher eukaryotes. However, the mechanism and selectivity of Pol II attenuation remains unclear. Our lab recently helped characterize a hybrid attenuation pathway involving Hrp1, an RNA-binding protein in the 3’-end cleavage factor (CF) complex, and the Sen1 helicase (Fig. 1C). The hybrid pathway appears to be an alternative to the canonical attenuation pathway in yeast, which relies on the RNA-binding proteins Nrd1/Nab3 and Sen1 (NNS). We hypothesize that Hrp1-dependent hybrid termination contributes broadly to yeast Pol II attenuation.
Our study of Pol II attenuation is significant because it will increase understanding of how RNA-based gene regulation evolves over time. Our work will inform analysis of the Hrp1 ortholog HNRNPDL, a human protein that likewise binds AU-rich RNA and regulates transcription. In addition, naturally-occurring and artificially-engineered attenuators may be harnessed for dynamic gene control in biotechnology applications, including yeast expression of industrial enzymes.
Kuehner Lab Approach
Using a combination of molecular biology (e.g. PCR, Gibson cloning), genetics (e.g. mutagenesis, CRISPR), biochemistry (e.g. lacZ reporter assay), and bioinformatics (genome browser analysis), we aim to generate a comprehensive profile of Pol II attenuation determinants (e.g. RNA-binding elements and protein recognition factors) and identify a myriad of new attenuators for further study. We ultimately hope to uncover novel attenuation mechanisms in the yeast model system that may be shared across species. In addition we aim to train future STEM professionals, and Kuehner lab alumni have successfully pursued careers in research (academia, industry), health care (PA, NP, RN), and government.